Walker 927 bottle jack series A, age?

[Dan nz]

Hi all, new member here, just hoping someone can give me a heads up on the age of this 927 walker bottle jack, was recently given to me by my grandfather, whos in his 80s, said it was his dads, so I assume its fairly old! It's getting the full TLC treatment, just can't seem to find any info on how to identify it, cheers

 

[Ole Slewfoot]

Just saying...